1 files changed, 2 insertions, 1 deletions
diff --git a/src/widget.cpp b/src/widget.cpp
index 320a34e80..f4a64f412 100644
--- a/src/widget.cpp
+++ b/src/widget.cpp
@@ -1693,7 +1693,8 @@ Dimension NWidgetLeaf::closebox_dimension  = {0, 0};
  */
 NWidgetLeaf::NWidgetLeaf(WidgetType tp, Colours colour, int index, uint16 data, StringID tip) : NWidgetCore(tp, colour, 1, 1, data, tip)
 {
-	this->SetIndex(index);
+	assert(index >= 0 || tp == WWT_LABEL || tp == WWT_TEXT);
+	if (index >= 0) this->SetIndex(index);
 	this->SetMinimalSize(0, 0);
 	this->SetResize(0, 0);